RGB-colors in .itermcolors (for iTerm): <real>-entities?

I'm trying to set my color-palette in iTerm, and are looking at the setup in the .itermcolors-files.

I've made it as far as to figure out that this color:

<key>Foreground Color</key>
<dict>
    <key>Blue Component</key>
    <real>0.67843139171600342</real>
    <key>Green Component</key>
    <real>0.67843139171600342</real>
    <key>Red Component</key>
    <real>0.67843139171600342</real>
</dict>

is the color: #BBBBBB or rgb(187, 187, 187). I've done this by applying a colorscheme in iTerm - and then inspecting that same colorscheme from the GUI.

And this color:

<key>Background Color</key>
<dict>
    <key>Blue Component</key>
    <real>0.12549020349979401</real>
    <key>Green Component</key>
    <real>0.12549020349979401</real>
    <key>Red Component</key>
    <real>0.12549020349979401</real>
</dict>

corresponds to 2b2b2b or rgb(43, 43, 43).

How is that conversion made from real-entities in the .itermcolors-files, to the hex-values that I get from the GUI for iTerm?